git ssb

1
var Value = require('./value')
2
var LazyWatcher = require('./lib/lazy-watcher')
3
var isSame = require('./lib/is-same')
4
var isObservable = require('./is-observable')
5
var resolve = require('./resolve')
6
var addCollectionMethods = require('./lib/add-collection-methods')
7
var forEach = require('./for-each')
8
9
module.exports = Array
10
11
function Array (defaultValues, opts) {
12
  var object = []
13
  var sources = []
14
  var objectReleases = []
15
  var fixedIndexing = opts && opts.fixedIndexing || false
16
17
  var releases = []
18
  var comparer = opts && opts.comparer || null
19
20
  var binder = LazyWatcher(update, listen, unlisten)
21
  binder.value = object
22
23
  if (opts && opts.idle) binder.idle = true
24
  if (opts && opts.nextTick) binder.nextTick = true
25
26
  if (defaultValues && defaultValues.length) {
27
    forEach(defaultValues, add)
28
  }
29
30
  var observable = function MutantArray (listener) {
31
    if (!listener) {
32
      return binder.getValue()
33
    }
34
    return binder.addListener(listener)
35
  }
36
37
  // getLength, get, indexOf, etc
38
  addCollectionMethods(observable, sources)
39
40
  observable.push = function (item) {
41
    var result = null
42
    if (arguments.length === 1) {
43
      result = add(item)
44
    } else {
45
      result = []
46
      for (var i = 0; i < arguments.length; i++) {
47
        result.push(add(arguments[i]))
48
      }
49
    }
50
    binder.broadcast()
51
    return result
52
  }
53
54
  observable.put = function (index, valueOrObs) {
55
    valueOrObs = getObsValue(valueOrObs)
56
    sources[index] = valueOrObs
57
    object[index] = resolve(valueOrObs)
58
    if (binder.live) {
59
      tryInvoke(objectReleases[index])
60
      objectReleases[index] = bind(valueOrObs)
61
    }
62
    binder.broadcast()
63
    return valueOrObs
64
  }
65
66
  observable.insert = function (valueOrObs, at) {
67
    valueOrObs = getObsValue(valueOrObs)
68
    sources.splice(at, 0, valueOrObs)
69
    if (binder.live) objectReleases.splice(at, 0, bind(valueOrObs))
70
    object.splice(at, 0, resolve(valueOrObs))
71
    binder.broadcast()
72
    return valueOrObs
73
  }
74
75
  observable.pop = function () {
76
    var result = sources.pop()
77
    if (binder.live) tryInvoke(objectReleases.pop())
78
    object.pop()
79
    binder.broadcast()
80
    return result
81
  }
82
83
  observable.shift = function () {
84
    var result = sources.shift()
85
    if (binder.live) tryInvoke(objectReleases.shift())
86
    object.shift()
87
    binder.broadcast()
88
    return result
89
  }
90
91
  observable.clear = function () {
92
    objectReleases.forEach(tryInvoke)
93
    sources.length = 0
94
    objectReleases.length = 0
95
    object.length = 0
96
    binder.broadcast()
97
  }
98
99
  observable.delete = function (valueOrObs) {
100
    observable.deleteAt(sources.indexOf(valueOrObs))
101
  }
102
103
  observable.deleteAt = function (index) {
104
    if (index >= 0 && index < sources.length) {
105
      sources.splice(index, 1)
106
      if (binder.live) objectReleases.splice(index, 1).forEach(tryInvoke)
107
      object.splice(index, 1)
108
      binder.broadcast()
109
    }
110
  }
111
112
  observable.transaction = function (cb) {
113
    binder.transaction(observable, cb)
114
  }
115
116
  observable.set = function (values) {
117
    var changed = false
118
    if (fixedIndexing) {
119
      var length = (values && values.length) || 0
120
      for (var i = 0; i < length; i++) {
121
        if (isObservable(values[i])) {
122
          if (values[i] !== sources[i]) {
123
            tryInvoke(objectReleases[i])
124
            sources[i] = values[i]
125
            object[i] = resolve(sources[i])
126
            changed = true
127
            if (binder.live) {
128
              objectReleases[i] = bind(sources[i])
129
            }
130
          }
131
        } else if (sources[i] && sources[i]._type === 'MutantArrayValue') {
132
          if (!isSame(sources[i](), values[i], comparer)) {
133
            sources[i].set(values[i])
134
            object[i] = resolve(sources[i])
135
            changed = true
136
          }
137
        } else {
138
          tryInvoke(objectReleases[i])
139
          sources[i] = getObsValue(values[i])
140
          object[i] = resolve(sources[i])
141
          changed = true
142
          if (binder.live) {
143
            objectReleases[i] = bind(sources[i])
144
          }
145
        }
146
      }
147
      for (var index = length; index < sources.length; index++) {
148
        tryInvoke(objectReleases[index])
149
        changed = true
150
      }
151
152
      if (changed) {
153
        objectReleases.length = length
154
        sources.length = length
155
        object.length = length
156
        binder.broadcast()
157
      }
158
    } else {
159
      unlisten()
160
      sources.length = 0
161
      objectReleases.length = 0
162
      object.length = 0
163
      forEach(values, add)
164
      if (binder.live) {
165
        listen()
166
        binder.broadcast()
167
      }
168
    }
169
  }
170
171
  return observable
172
173
  // scoped
174
175
  function getObsValue (valueOrObs) {
176
    if (fixedIndexing && !isObservable(valueOrObs)) {
177
      valueOrObs = Value(valueOrObs)
178
      valueOrObs._type = 'MutantArrayValue'
179
    }
180
    return valueOrObs
181
  }
182
183
  function add (valueOrObs) {
184
    valueOrObs = getObsValue(valueOrObs)
185
    sources.push(valueOrObs)
186
    object.push(resolve(valueOrObs))
187
    if (binder.live) {
188
      objectReleases.push(bind(valueOrObs))
189
    }
190
    return valueOrObs
191
  }
192
193
  function bind (valueOrObs) {
194
    return typeof valueOrObs === 'function' ? valueOrObs(binder.onUpdate) : null
195
  }
196
197
  function listen () {
198
    sources.forEach(function (obs, i) {
199
      objectReleases[i] = bind(obs)
200
    })
201
202
    if (opts && opts.onListen) {
203
      var release = opts.onListen()
204
      if (typeof release === 'function') {
205
        releases.push(release)
206
      }
207
    }
208
  }
209
210
  function unlisten () {
211
    objectReleases.forEach(tryInvoke)
212
    objectReleases.length = 0
213
214
    while (releases.length) {
215
      tryInvoke(releases.pop())
216
    }
217
218
    if (opts && opts.onUnlisten) {
219
      opts.onUnlisten()
220
    }
221
  }
222
223
  function update () {
224
    var changed = false
225
    sources.forEach(function (source, i) {
226
      var newValue = resolve(source)
227
      if (!isSame(newValue, object[i], comparer)) {
228
        object[i] = newValue
229
        changed = true
230
      }
231
    })
232
    return changed
233
  }
234
}
235
236
function tryInvoke (func) {
237
  if (typeof func === 'function') {
238
    func()
239
  }
240
}
241